Registration Dossier

Administrative data

Endpoint:
acute toxicity: inhalation
Type of information:
migrated information: read-across from supporting substance (structural analogue or surrogate)
Adequacy of study:
key study
Study period:
1996-06-21 until 1995-07-12
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
other: Scientifically valid study, OECD guideline study. Please refer to IUCLID section 13 for read-across justification.

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
1996
Report Date:
1996

Materials and methods

Test guidelineopen allclose all
Qualifier:
according to
Guideline:
OECD Guideline 403 (Acute Inhalation Toxicity)
Deviations:
no
Qualifier:
according to
Guideline:
EU Method B.2 (Acute Toxicity (Inhalation))
Deviations:
no
Qualifier:
according to
Guideline:
EPA OPP 81-3 (Acute inhalation toxicity)
Deviations:
no
GLP compliance:
yes
Test type:
standard acute method
Limit test:
yes

Test material

Reference
Name:
Unnamed
Type:
Constituent
Type:
Constituent
Test material form:
solid: particulate/powder
Remarks:
migrated information: powder

Test animals

Species:
rat
Strain:
Sprague-Dawley
Sex:
male/female
Details on test animals and environmental conditions:
TEST ANIMALS
- Source: Charles River UK Ltd, Manston Road, Margate, Kent, England
- Age at study initiation: 8 weeks
- Weight at study initiation: 200 - 300 g
- Housing: The holding cages were made of stainless steel sheet and wire mesh and were suspended on a movable rack.
- Diet: SDS RM1
- Water: tap water
- Acclimation period: 5 days

ENVIRONMENTAL CONDITIONS
- Temperature: 18 - 24°C
- Humidity: 45 - 78 %

Administration / exposure

Route of administration:
inhalation: dust
Type of inhalation exposure:
nose only
Vehicle:
air
Details on inhalation exposure:
GENERATION OF TEST ATMOSPHERE / CHAMBER DESCRIPTION
- Exposure apparatus: A Wright dust generator was used to produce the test atmospheres containing the dust of the test substance
- Exposure chamber volume: 5 L
- Method of holding animals in test chamber: The snout-only exposure chambers were of cylindrical form and made of aluminium alloy. The rats were held for exposure, individually, in polycarbonate restraining tubes attached at one of the ports in the cylindrical section of the chamber. The tube was tapered at one end to allow the snout only to project into the chamber. The other end was closed by insertion of an expanded plastic bung. A push rod passed through the centre of the bung and was adjustable to maintain the position of the rats during exposure.
- Source and rate of air: A supply of clean dried compressed air was connected to the dust generator and the supply pressure was adjusted to give a flow rate of 14 litres per minute measured at the generator outlet nozzle. The total chamber air supply was made up to 15 1/minute with an additional flow of 11/minute into the diluent port of the chamber.
- Method of conditioning air: The test atmosphere was passed through an elutriation column to reduce, by sedimentation, the amount of non-respirable particulate in the test atmosphere.
- Temperature, humidity: 21°C, 25 %

TEST ATMOSPHERE
- Brief description of analytical method used: Five air samples were taken from the chamber during the exposure to determine the concentration of the test substance in the chamber air by chemical analysis. Samples were collected at 30, 60, 120, 180 and 235 minutes following the equilibrium period. Each air sample was withdrawn, at 4 litres per minute, through a weighed glass fibre filter mounted in an open face filter holder. The volume of the air sample was measured with a wet-type gas meter. Two additional air samples were taken during each exposure using a Marple cascade impactor. The samples were taken approximately 1.5 and 3.5 hours after the start of exposure. The material collected on the stages of the sampler was analysed to determine the particle size distribution of the test subsrance in the test atmospheres.
- Samples taken from breathing zone: yes

Analytical verification of test atmosphere concentrations:
yes
Duration of exposure:
4 h
Concentrations:
Mean analysis concentration: 2.93 mg/L
Mean gravimetric concentration: 3.14 mg/L
Nominal concentration (the nominal concentration is calculated from the amount of the test substance disperrsed and the total volume of air supplied to the exposure system): 17.5 mg/L
No. of animals per sex per dose:
10 animals: 5 males, 5 females
Control animals:
yes
Details on study design:
- Duration of observation period following administration: 14 days
- Frequency of observations and weighing: daily
- Necropsy of survivors performed: yes
- Other examinations performed: clinical signs, body weight, organ weights, histopathology

Results and discussion

Effect levels
Sex:
male/female
Dose descriptor:
LC50
Effect level:
> 2.93 mg/L air (analytical)
Based on:
test mat.
Exp. duration:
4 h
Mortality:
No mortality was observed
Clinical signs:
other: During exposure - There were no signs attributable to exposure to the test substance in the test rats. Soiling of the fur with as a consequence of the method of restraint was seen in control and test rats. During observation period - The only sign was exc
Body weight:
Reduced bodyweight or a reduced rate of bodyweight gain was seen in rats exposed to the test substance for 1 day. Subsequently, weight gain was similar to that of control rats.
Gross pathology:
- The lung weight to bodyweight ratios for rats exposed to the test substance were similar to those of the control rats
- There were no internal or external macroscopic abnormalities detected in rats exposed to the test substance
- No treatment-related changes were detected.
Other findings:
Water consumption:
Water consumption was slightly increased for 2 days following exposure to the test substance. Subsequently, water consumption for test rats was similar to that of the control rats.

Any other information on results incl. tables

- The size distribution results from the chemical analysis: 3.5 µm (MMAD) and 80.8 % of respirable particles (< 7 µm)

Applicant's summary and conclusion